HelloSelenium

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.*;

/**
 * Created by Saifur on 2/14/2015.
 */
public class HelloSelenium {

    WebDriver driver;
    String url = "https://github.com/";

    @BeforeClass
    public void SertUpTest(){
        System.setProperty("webdriver.chrome.driver", "\\working\\Seleniumjava\\drivers\\chromedriver.exe");
        //System.setProperty("webdriver.ie.driver", "\\working\\Seleniumjava\\drivers\\IEDriverServer.exe");
        driver = new ChromeDriver();
        //driver = new FirefoxDriver();
        //driver = new InternetExplorerDriver();

        driver.navigate().to(url);
        driver.manage().window().maximize();


    }

    @AfterClass
    public void CleaUpDriver(){

        driver.quit();
    }
}

TestClass1

import org.openqa.selenium.By;
import org.testng.Assert;
import org.testng.annotations.Test;

/**
 * Created by Saifur on 3/12/2015.
 */

public class TestClass1 extends HelloSelenium {

    @Test
    public void DemoTest() throws InterruptedException {

        driver.findElement(By.cssSelector(".js-site-search-form>input")).sendKeys("TestClass1");
    }
}

TestClass2

import org.openqa.selenium.By;
import org.testng.annotations.Test;

/**
 * Created by Saifur on 3/12/2015.
 */
public class TestClass2 extends HelloSelenium {
    @Test
    public void DemoTest() throws InterruptedException {

        driver.findElement(By.cssSelector(".js-site-search-form>input")).sendKeys("TestClass2");
    }
}